Carolyn McCormick was in the H:LOTS episodes "Sniper 1" and "Sniper 2"; she played Mrs. William Mariner.
Synopsis of the "Sniper" episodes from here
A series of sniper shootings and a hangman game scrawled at the sniper's vantage points prompt a red ball investigation. The sniper eventually kills nine people, and based on his record, is scheduled to kill again soon when a handwriting expert matches the handwriting in the game to the signature of William Mariner, on a credit card receipt from a purchase of chalk. When the detectives descend on Mariner's house, they find him holed up in his den - his wife says he keeps a rifle there. Bayliss tries to talk him out, but he asks Bayliss for a letter to finish the game. Bayliss guesses correctly, and Mariner shoots himself. Barnfather, who has increasingly been critical of Russert, fires her as captain; when she calls him on it, he demotes her down to detective. Another sniper takes up the dead sniper's time table, killing three, and the whole squad heads back to the station from their homes. The shootings have gotten Munch worried, and he endeavors to make sure Howard is safely out of any line of fire while he with her, not wanting to see her shot again. G calls Russert in to help with the red ball. Another shooting kills several people in a bus. Alex Robey, a witness to the earlier shooting, turns up at the site of the latest shooting - they take him in for questioning. Bayliss and Pembleton determine that Robey did not know Mariner. Russert talks to Robey and he confesses to the second series of shootings, saying that Mariner stole his idea, that he is an original, not a copycat.
Synopsis: "Sniper 1"
"Sniper 2" Review
Two maps from "Sniper", here and here.